Up to now, carbon black-based pigments and iron oxide-based pigments have been general as black pigments that are used as colorants for paints, printing inks, and plastics. These black pigments exhibit a black color by absorbing all the rays of light including visible light region of sunlight.
The black pigments (carbon black-based pigments in particular) absorb light in a visible light region (about 380 to about 780 nm) to exhibit a black color, but in fact, also absorbs light that is in a near-infrared region including a wavelength region of 800 to 1,400 nm and that greatly contributes to heat. Therefore, there has been a problem that the temperature of articles colored by the black pigments as described above rise easily by being irradiated with sunlight. In addition, as articles colored by a black pigment, sophisticated products such as a black matrix for a color filter have appeared in recent years. Thus, various studies have been made on a black pigment that does not cause temperature rise even if it is irradiated with sunlight, a colorant (coloring composition) for use in coloring an article into black, and the like.
For example, there is proposed an azomethine group-containing black azo pigment that does not absorb light in the infrared region (infrared radiation) while exhibiting a black color by absorbing light in the visible region (Patent Literature 1). Patent Literature 1 discloses that an article the temperature of which does not rise excessively due to direct sunlight or the like can be obtained by using a colorant containing this black azo pigment.
In addition, there is proposed an azo pigment obtained by using, as a diazo component, a compound represented by the following formula (A) (Patent Literature 2).
